Deleting services from %desktop-services in operating system declaration

Deleting services from %desktop-services in operating system declaration

[swedebugia]

Hi

I have trouble getting the syntax right to delete avahi and wicd from my 
config.scm.

This did not work (inspecting with the REPL):
   (services (cons* (tor-service) %desktop-services))
   (modify-services (alist-delete
		     wicd-service
		     %desktop-services))
   (modify-services (alist-delete
		     avahi-service
		     %desktop-services))

Neither this:
   (services (cons* (tor-service) %desktop-services))
   (modify-services (alist-delete
		     wicd-service
		     avahi-service
		     %desktop-services))

The manual does not yet have examples of how to delete one or more 
entries from the %base-services or other lists.

Help would be appreciated :)

cheers
swedebugia

Re: Deleting services from %desktop-services in operating system declaration

[Efraim Flashner]

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On Wed, 20 Jan 2016 13:42:11 +0100
swedebugia@riseup.net wrote:

> Hi
> 
> I have trouble getting the syntax right to delete avahi and wicd from my 
> config.scm.
> 
> This did not work (inspecting with the REPL):
>    (services (cons* (tor-service) %desktop-services))
>    (modify-services (alist-delete
> 		     wicd-service
> 		     %desktop-services))
>    (modify-services (alist-delete
> 		     avahi-service
> 		     %desktop-services))
> 
> Neither this:
>    (services (cons* (tor-service) %desktop-services))
>    (modify-services (alist-delete
> 		     wicd-service
> 		     avahi-service
> 		     %desktop-services))
> 
> The manual does not yet have examples of how to delete one or more 
> entries from the %base-services or other lists.
> 
> Help would be appreciated :)
> 
> cheers
> swedebugia
> 

I haven't written any config.scm files, but if it's like the python packages
this might work:

(services (cons* (tor-service)
                 (fold alist-delete %desktop-services
                                    '("wicd-service" "avahi-service"))))

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Re: Deleting services from %desktop-services in operating system declaration

[Thompson, David]

On Wed, Jan 20, 2016 at 7:42 AM,  <swedebugia@riseup.net> wrote:
> Hi
>
> I have trouble getting the syntax right to delete avahi and wicd from my
> config.scm.
>
> This did not work (inspecting with the REPL):
>   (services (cons* (tor-service) %desktop-services))
>   (modify-services (alist-delete
>                      wicd-service
>                      %desktop-services))
>   (modify-services (alist-delete
>                      avahi-service
>                      %desktop-services))
>
> Neither this:
>   (services (cons* (tor-service) %desktop-services))
>   (modify-services (alist-delete
>                      wicd-service
>                      avahi-service
>                      %desktop-services))
>
> The manual does not yet have examples of how to delete one or more entries
> from the %base-services or other lists.
>
> Help would be appreciated :)

First of all, %desktop-services is *not* an alist, so using
alist-delete certainly won't work.  Second, modify-services is
*syntax*, so the form (alist-delete ...) is surely the wrong syntax.

Below is the docstring for modify-services:

Modify the services listed in SERVICES according to CLAUSES.  Each clause
must have the form:

  (TYPE VARIABLE => BODY)

where TYPE is a service type, such as 'guix-service-type', and VARIABLE is an
identifier that is bound within BODY to the value of the service of that
TYPE.  Consider this example:

  (modify-services %base-services
    (guix-service-type config =>
                       (guix-configuration
                        (inherit config)
                        (use-substitutes? #f)
                        (extra-options '(\"--gc-keep-derivations\"))))
    (mingetty-service-type config =>
                           (mingetty-configuration
                            (inherit config)
                            (motd (plain-file \"motd\" \"Hi there!\")))))

It changes the configuration of the GUIX-SERVICE-TYPE instance, and that of
all the MINGETTY-SERVICE-TYPE instances.

This is a shorthand for (map (lambda (svc) ...) %base-services).



Hopefully that provides enough of an example for you!  You can
retrieve the documentation associated with an object at the Guile
REPL.  Here's how you'd get this one:

$ ./pre-inst-env guile
GNU Guile 2.0.11
Copyright (C) 1995-2014 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> ,use (gnu services)
scheme@(guile-user)> ,describe modify-services

- Dave

Re: Deleting services from %desktop-services in operating system declaration

[Ludovic Courtès]

swedebugia@riseup.net skribis:

> I have trouble getting the syntax right to delete avahi and wicd from
> my config.scm.

The correct syntax would be:

  (operating-system
    ;; …
    (services (remove (lambda (service)
                        (or (eq? (service-kind service)
                                 wicd-service-type)
                            (eq? (service-kind service)
                                 avahi-service-type)))
                      %desktop-services)))

As David notes, ‘%desktop-services’ is a list of service objects.  To
remove elements from a list, the right procedure is ‘remove’ (info
"(guile) SRFI-1 Filtering and Partitioning").

> The manual does not yet have examples of how to delete one or more
> entries from the %base-services or other lists.

I’ve added this example in commit 5d94ac5.

HTH!

Ludo’.

Re: Deleting services from %desktop-services in operating system declaration

[swedebugia]

On 2016-01-21 00:24, ludo@gnu.org wrote:
> swedebugia@riseup.net skribis:
> 
>> I have trouble getting the syntax right to delete avahi and wicd from
>> my config.scm.
> 
> The correct syntax would be:
> 
>   (operating-system
>     ;; …
>     (services (remove (lambda (service)
>                         (or (eq? (service-kind service)
>                                  wicd-service-type)
>                             (eq? (service-kind service)
>                                  avahi-service-type)))
>                       %desktop-services)))

I tried this and got this error:
# guix system reconfigure /etc/config/config.scm
guix system: error: failed to load '/etc/config/config.scm':
/etc/config/config.scm:48:12: In procedure #<procedure a7c3530 ()>:
/etc/config/config.scm:48:12: In procedure module-lookup: Unbound 
variable: remove

Config here: https://paste.debian.net/367385/

> As David notes, ‘%desktop-services’ is a list of service objects.  To
> remove elements from a list, the right procedure is ‘remove’ (info
> "(guile) SRFI-1 Filtering and Partitioning").

Thanks for the tip!

>> The manual does not yet have examples of how to delete one or more
>> entries from the %base-services or other lists.
> 
> I’ve added this example in commit 5d94ac5.

:)

cheers
sdb

Re: Deleting services from %desktop-services in operating system declaration

[Alex Kost]

swedebugia@riseup.net (2016-01-23 16:09 +0300) wrote:

> On 2016-01-21 00:24, ludo@gnu.org wrote:
>> swedebugia@riseup.net skribis:
>>
>>> I have trouble getting the syntax right to delete avahi and wicd from
>>> my config.scm.
>>
>> The correct syntax would be:
>>
>>   (operating-system
>>     ;; …
>>     (services (remove (lambda (service)
>>                         (or (eq? (service-kind service)
>>                                  wicd-service-type)
>>                             (eq? (service-kind service)
>>                                  avahi-service-type)))
>>                       %desktop-services)))
>
> I tried this and got this error:
> # guix system reconfigure /etc/config/config.scm
> guix system: error: failed to load '/etc/config/config.scm':
> /etc/config/config.scm:48:12: In procedure #<procedure a7c3530 ()>:
> /etc/config/config.scm:48:12: In procedure module-lookup: Unbound
> variable: remove

'remove' procedure is from (srfi srfi-1) module, so you need to use it
in your config (see below).

Note that after fixing it, you'll get complaints about other unbound
variables:

- 'avahi-service-type': it is from (gnu services avahi);

- 'tor-service': it is from (gnu services networking);

- 'wicd-service-type': it is also from (gnu services networking), but it
  is not exported (I think we should fix it), so now you have to use it
  like this:

  (@@ (gnu services networking) wicd-service-type)

  which means: "give me 'wicd-service-type' from (gnu services
  networking) module, and I don't care if it's not exported".

> Config here: https://paste.debian.net/367385/

I paste your config here for convenience:

> (use-modules (gnu) (gnu system nss))

(use-modules
 (gnu)
 (gnu system nss)
 (srfi srfi-1))

> (use-service-modules desktop)
> (use-package-modules xfce ratpoison certs)

> (operating-system
>   (host-name "unknown")
>   (timezone "Europe/Stockholm")
>   (locale "en_US.UTF-8")

>   ;; Assuming /dev/sdX is the target hard disk, and "root" is
>   ;; the label of the target root file system.
>   (bootloader (grub-configuration (device "/dev/sda")))
>   (file-systems (cons* (file-system
>                         (device "guix")
>                         (title 'label)
>                         (mount-point "/")
>                         (type "ext4"))

>   		      (file-system
>                         (device "home")
>                         (title 'label)
>                         (mount-point "/home")
>                         (type "ext4"))
>                       %base-file-systems))

>   (swap-devices '("/dev/sdb3"))

>   (users (cons (user-account
>                 (name "sdb")
>                 (comment "swedebugia")
>                 (group "users")
>                 (supplementary-groups '("wheel" "netdev"
>                                         "audio" "video"))
>                 (home-directory "/home/sdb"))
>                %base-user-accounts))

>   ;; Add Xfce and Ratpoison; that allows us to choose
>   ;; sessions using either of these at the log-in screen.
>   (packages (cons* xfce ratpoison    ;desktop environments
>                    nss-certs         ;for HTTPS access
>                    %base-packages))

>   ;; Use the "desktop" services, which include the X11
>   ;; log-in service, networking with Wicd, and more.
>   (services (remove (lambda (service)
>                         (or (eq? (service-kind service)
>                                  wicd-service-type)
>                             (eq? (service-kind service)
>                                  avahi-service-type)))
>                       %desktop-services))
>   (services (cons* (tor-service) %desktop-services))

You shouldn't (!) use 'services' (or any other operating-system field
more than *ONCE*).  You can combine 'cons*' and 'remove' like this:

  (services
   (cons* (tor-service)
          (remove (lambda (service)
                    (or (eq? (service-kind service)
                             avahi-service-type)
                        (eq? (service-kind service)
                             (@@ (gnu services networking) wicd-service-type))
                        (eq? (service-kind service)
                             (@@ (gnu services networking) ntp-service-type))))
                  %desktop-services)))

Note: if you want to remove wicd service, you also need to remove ntp
service, otherwise you'll get:

  guix system: error: service 'ntpd' requires 'networking', which is undefined

>   ;; Allow resolution of '.local' host names with mDNS.
>   (name-service-switch %mdns-host-lookup-nss))

-- 
Alex

Re: Deleting services from %desktop-services in operating system declaration

[swedebugia]

On 2016-01-23 17:43, Alex Kost wrote:
> swedebugia@riseup.net (2016-01-23 16:09 +0300) wrote:
> 
>> On 2016-01-21 00:24, ludo@gnu.org wrote:
>>> swedebugia@riseup.net skribis:
>>> 
>>>> I have trouble getting the syntax right to delete avahi and wicd 
>>>> from
>>>> my config.scm.
>>> 
>>> The correct syntax would be:
>>> 
>>>   (operating-system
>>>     ;; …
>>>     (services (remove (lambda (service)
>>>                         (or (eq? (service-kind service)
>>>                                  wicd-service-type)
>>>                             (eq? (service-kind service)
>>>                                  avahi-service-type)))
>>>                       %desktop-services)))
>> 
>> I tried this and got this error:
>> # guix system reconfigure /etc/config/config.scm
>> guix system: error: failed to load '/etc/config/config.scm':
>> /etc/config/config.scm:48:12: In procedure #<procedure a7c3530 ()>:
>> /etc/config/config.scm:48:12: In procedure module-lookup: Unbound
>> variable: remove
> 
> 'remove' procedure is from (srfi srfi-1) module, so you need to use it
> in your config (see below).
> 
> Note that after fixing it, you'll get complaints about other unbound
> variables:
> 
> - 'avahi-service-type': it is from (gnu services avahi);
> 
> - 'tor-service': it is from (gnu services networking);
> 
> - 'wicd-service-type': it is also from (gnu services networking), but 
> it
>   is not exported (I think we should fix it), so now you have to use it
>   like this:
> 
>   (@@ (gnu services networking) wicd-service-type)
> 
>   which means: "give me 'wicd-service-type' from (gnu services
>   networking) module, and I don't care if it's not exported".
> 
>> Config here: https://paste.debian.net/367385/
> 
> I paste your config here for convenience:
> 
>> (use-modules (gnu) (gnu system nss))
> 
> (use-modules
>  (gnu)
>  (gnu system nss)
>  (srfi srfi-1))
> 
>> (use-service-modules desktop)
>> (use-package-modules xfce ratpoison certs)
> 
>> (operating-system
>>   (host-name "unknown")
>>   (timezone "Europe/Stockholm")
>>   (locale "en_US.UTF-8")
> 
>>   ;; Assuming /dev/sdX is the target hard disk, and "root" is
>>   ;; the label of the target root file system.
>>   (bootloader (grub-configuration (device "/dev/sda")))
>>   (file-systems (cons* (file-system
>>                         (device "guix")
>>                         (title 'label)
>>                         (mount-point "/")
>>                         (type "ext4"))
> 
>>   		      (file-system
>>                         (device "home")
>>                         (title 'label)
>>                         (mount-point "/home")
>>                         (type "ext4"))
>>                       %base-file-systems))
> 
>>   (swap-devices '("/dev/sdb3"))
> 
>>   (users (cons (user-account
>>                 (name "sdb")
>>                 (comment "swedebugia")
>>                 (group "users")
>>                 (supplementary-groups '("wheel" "netdev"
>>                                         "audio" "video"))
>>                 (home-directory "/home/sdb"))
>>                %base-user-accounts))
> 
>>   ;; Add Xfce and Ratpoison; that allows us to choose
>>   ;; sessions using either of these at the log-in screen.
>>   (packages (cons* xfce ratpoison    ;desktop environments
>>                    nss-certs         ;for HTTPS access
>>                    %base-packages))
> 
>>   ;; Use the "desktop" services, which include the X11
>>   ;; log-in service, networking with Wicd, and more.
>>   (services (remove (lambda (service)
>>                         (or (eq? (service-kind service)
>>                                  wicd-service-type)
>>                             (eq? (service-kind service)
>>                                  avahi-service-type)))
>>                       %desktop-services))
>>   (services (cons* (tor-service) %desktop-services))
> 
> You shouldn't (!) use 'services' (or any other operating-system field
> more than *ONCE*).  You can combine 'cons*' and 'remove' like this:
> 
>   (services
>    (cons* (tor-service)
>           (remove (lambda (service)
>                     (or (eq? (service-kind service)
>                              avahi-service-type)
>                         (eq? (service-kind service)
>                              (@@ (gnu services networking) 
> wicd-service-type))
>                         (eq? (service-kind service)
>                              (@@ (gnu services networking) 
> ntp-service-type))))
>                   %desktop-services)))

Thanks for the tip on how to combine them!

> 
> Note: if you want to remove wicd service, you also need to remove ntp
> service, otherwise you'll get:
> 
>   guix system: error: service 'ntpd' requires 'networking', which is 
> undefined

I got this error a couple of times. Thanks for the explanation - this 
was really helpful in getting my config to work properly.

I decided to keep wicd after all and just removed avahi. It seems that 
avahi is also not exported.

The full config with my comments is found here: 
https://paste.debian.net/368031/

I'm effectively learning Scheme/Guile while trying to hack GuixSD and I 
like it :D

cheers
sdb

Re: Deleting services from %desktop-services in operating system declaration

[Alex Kost]

swedebugia@riseup.net (2016-01-25 14:20 +0300) wrote:

> On 2016-01-23 17:43, Alex Kost wrote:
[...]
>> Note: if you want to remove wicd service, you also need to remove ntp
>> service, otherwise you'll get:
>>
>>   guix system: error: service 'ntpd' requires 'networking', which is
>> undefined
>
> I got this error a couple of times. Thanks for the explanation - this
> was really helpful in getting my config to work properly.
>
> I decided to keep wicd after all and just removed avahi.

If you don't like wicd, you can use another service that provides
'networking': there are 'dhcp-client-service' and
'static-networking-service' services for this purpose.  So if you want
to remove wicd and to use dhcp service instead, you can do it like this:

  (services
   (cons* (tor-service)
          (dhcp-client-service)
	  (remove (lambda (service)
		    (or (eq? (service-kind service)
                             (@@ (gnu services networking)
                                 wicd-service-type))
                        (eq? (service-kind service)
                             avahi-service-type)))
		  %desktop-services)))

> It seems that avahi is also not exported.

Actually 'avahi-service-type' is exported¹, so you can use it instead of
(@@ (gnu services avahi) avahi-service-type).

> The full config with my comments is found here:
> https://paste.debian.net/368031/

> (use-modules (gnu)
> 	     (gnu system nss)
> 	     (srfi srfi-1)		; Needed to use 'remove' below
> 	     (gnu services avahi)	; Needed to remove avahi
> 	     (gnu services networking))	; Needed to add tor-service
> (use-service-modules desktop)
> (use-package-modules xfce ratpoison certs)

Just in case you didn't know: (use-service-modules desktop) is exactly
the same as (use-modules (gnu services desktop))

So you can use:

  (use-service-modules desktop avahi networking)

instead of specifying (gnu services avahi) and (gnu services networking)
in 'use-modules', if you like it.

> I'm effectively learning Scheme/Guile while trying to hack GuixSD and I
> like it :D

I like Guile and Guix too!

http://git.savannah.gnu.org/cgit/guix.git/tree/gnu/services/avahi.scm#n30

-- 
Alex